It has been really cold for the last few days and heat is working but is not reaching desired temperature. It shuts off and then starts again. Reaches about 6 degrees below desired temperature and once shut off, the temperature drops significantly and then it starts working again. The furnace seems to work fine when it is on but need to understand why it doesn't reach desired temperature.
The temperature set on the thermostat may not be in line with the temperature displayed on monitor.It happens on reaching upon the set temperature,when it trips,it goes to a lesser temperature.The working of the thermostat seems to be faulty.
Would expect you need a new furnace since you also are having cycling problems. Check the plenium temps and the air temps just out of the registers.
Sounds like it may be your high limit switch is opening up which will cut the furnace off if the heat exchanger temp. gets to hot. This is a safety and it will auto reset once the temp. in the heat exchanger cools down and then the furnace will start working again. Cause: Bad air flow - dirty filter, dirty coils Bad high limit - opening up at the wrong temp.
